The present invention relates to a cutting tap and, more particularly, relates to a method of making a cutting tap with a correction grind.
Mechanisms and machine components requiring screw threads have had a long history in many technologies. In this regard, the use of screw threads as a fastener component has consistently dominated over all other means to join component parts into assemblies. Thus, it can be appreciated that articles used to form screw threads are essential to many manufacturing technologies.
Although there are many ways to generate internal screw threads, cutting taps are the favored way to generate an internal screw thread. One known tapping method to generate internal screw threads includes cutting material from the wall of a hole and then removing the same to produce a helical V-shaped screw thread. In the alternative, material can be displaced to form an internal screw thread.
Known cutting taps for blind holes typically include one or more spiral or helical flutes to facilitate chip removal during the thread cutting process. A correction grind can be provided, which is generally a secondary or small flute at the front of the tap that is superimposed upon a primary or main flute of the tap to change cutting characteristics in the cutting zone. This type of correction grind is formed or made as a secondary grinding operation. As a result, there is always a sharp, distinct transition between the correction grind and the main flute. This transition zone can be detrimental to tap performance because the cutting geometry changes abruptly there.
Accordingly, there has been identified a need for an improved cutting tap that overcomes limitations, shortcomings and disadvantages of known cutting taps. There has also been identified a need for an improved method of making a cutting tap that overcomes limitations, shortcomings and disadvantages of known methods of making cutting taps.